Bearing seal for rotary shafts



Jan. 14, 1936. g J, LE wzmsas BEARING SEAL FOR ROTARY SHAFTS Filed Oct. 29, 1934 2 Sheets-Sheet l ATTORNEYJ.

BEARING SEAL FOR ROTARY SHAFTS Filed Oct. 29, 1934 2 Sheets-Sheet 2 m mm A 1 W W J a ATTORNEYJ.

Patented Jan. 14, 1936 UNITED STATES PATENT GFFWE Schwitzer-Cummins, Company,

- Ind., a corporation Indianapolis,

Application October 29, 1934, Serial No. 750,398

3 Claims. (01. 286-11) This invention relates to an improvement in seals, particularly seals for fluid pumps, such as the water pump of an internal combustion engine. As applied to a rotary shaft, it is adapted to eliminate or minimize leakage from the fluid chamber between the drive shaft and its bearing.

One feature of the invention resides in the employment of a flexible sealing member, which may be preferably formed of rubber or the like, which will flex into sealing relation with the surface of the shaft while freely permitting relative longitudinal movement or end play between the shaft and bearing, as well as to compensate for wear in the sealing washer. Thus, the seal herein disclosed may freely move with the 'shaft as distinguished from sliding thereon and failing to function as a result of sticking due to tightness, corrosion. or roughness of the shaft.

Another feature of the invention resides in the mounting of such a seal within a recessed portion or cup provided for the purpose and formed or cast in the hub of an impeller for water pumps, and wherein the seal and impeller are positioned in the pump chamber. By means of this arrangement water and sediment is prevented from entering the seal and affecting the yielding sealing member therein. I

Another feature of the invention resides in the unitary relation of the impeller and seal whereby they may be assembled together and furnished as a unit for replacement. By thus assembling them for replacement, they may be more readily mounted in place on the pump shaft by the mechanic and the seal is thereby more perfectly fitted in place. This arrangement eliminates the necessity of the mechanic assembling the various parts of the seal independently of the impeller when making installation.

Another feature of the invention resides in the use of a carbon washer which is novel and more efficient and lasting than the usual washers commonly employed, such as cork, treated fabric, bronze or similar material. Washers of the latter materials would not readily slide on the shaft should the surface thereof become corroded. They also require lubrication and their sealing surfaces would become defective upon being scratched or torn by particles of grit. This difficulty is avoided in the use of a carbon washer which has the properties of not requiring lubrication, comprises a smooth sealing surface, and is readily slidable over the surfaces of a corroded shaft without sticking. Thus, in tests applied to all such materials, a carbon washer is found to be outstanding in these several advantages over the others.

The full nature of the invention will be understood from the accompanying drawings and the following description and claims:

Fig. 1 is a central vertical section through the bearing and seal with the shaft shown in elevation. Fig. 2 is a central vertical section through 10 the seal in expanded non-sealing position. Fig.

3 is a section taken on the line 3-3 of Fig. 1. Fig. 4 is a section taken on the line l-4 of Fig.

1. Fig. 5 is a perspective view of a unitary impeller with the seal mounted therein. Fig. 6 35 is a central vertical section through a portion of a pump housing showing the impeller and sealing ring mounting.

In the drawings there is shown a drive shaft rotatably mounted in a bearing H supported in a housing l2 of a water pump or similar fluid-containing device. The liquid seal, forming the feature of this invention, is secured to the shaft ID to bear against the outer end of the bearing II externally of the housing i2 for preventing fluid contained therein from leaking between the bearing H and shaft i0 during the rotation of the latter.

The seal comprises a carbon washer 83 which closely surrounds the shaft I0, rotating therewith and providing a sealing as well as a bearing surface against'the outer end of the bearing ii. Also mounted about the shaft there is a flexible seal which may preferably be formed of rubber having a thick semirigid ring M at one end and a similar ring H5 at the other end provided with the annular ribs i6 bearing directly against one face of the washer 53. Intermediate the rings i4 and Hi there is a thin flexible outer neck portion ll connected with an inner neck portion i8 by a flexible shoulder l9. As indicated in Fig. l, the shoulder it is adapted to flex to permit the outer portion H to overlap the inner portion l8 when the seal is secured in operative position.

A metal housing or cup 20 is provided to house the seal, which cup has a recess 29 for receiving a pin 22 extending through an opening in the shaft i0 as indicated by the dotted lines 23.

The inner or open end of the cup 20 is pro- 50 vided with diametrically disposed outwardly projecting flanges 24 embracing longitudinal slots for receiving the projections 25 formed about the periphery of the washer l3 and extending radially therefrom. Thus, the cup 20 is keyed to the shaft I3 by the pin 22 and to the washer I3 by the projections 25.

Contained within the cup 23 there is a compression spring 23 having one end bearing against the closed end of the cup and the other end bearing against the ring I5 of the flexible seal through the medium of a metal spring guide or sleeve 21. The ring II of the seal is protected by a metal clamp ring 23.

In assembly, but before securing the seal to the shaft, the parts are as illustrated in Fig. 2, with the spring and flexible seal expanded and the slots formed by the flanges 24 in the cup out of engagement with the projections 25 of the washer. In such position the cup is forced inwardly to compress the spring 26 and collapse the flexible seal, as illustrated in Fig. 1, whereupon the pin 22 is inserted through the opening of the shaft so that its ends will lie within the recessed portion 2I of the cup. In this operative position, the entire seal will rotate with the shaft relative to the bearing. The spring 26 will hold the adjacent surfaces of the washer and bearing in sealing engagement while rotating relative to each other, and will also maintain constant sealing pressure between the ring 25 of the flexible seal and the corresponding surface of the washer I3. In its compressed operative position the flexible seal is caused to double up on itself, as shown in Fig. 1, so that the inner portion I8 will be compressed in sealing relation against the periphery of the shaft by the shoulder portion I9. The shoulder portion I9 permits variation in length of the seal while still maintaining the sealing relation of the inner portion I8, as well as the ring portion I5. Such variation, as above stated, may be caused by variation in thickness of the parts and wear, as well as longitudinal displacement of the shaft due to end thrust forces, bearing clearance and the like.

While the invention has been herein disclosed as being applicable to a water pump shaft, it will be clear that the same principle in varying forms may be equally well utilized in different structures and under difierent conditions for functioning in the same manner and serving the same purpose.

Referring to the unitary structure and seal illustrated in Figs. 5 and 6, the pump housing 30 embraces a. pump chamber 3|, said housing having a. bearing 32 through which the shaft 33 extends. The end of the pump housing is removable from the main portion thereof through the medium of the bolts 34.

As illustrated in Fig. 6, there is a unitary structure comprising the impeller 35 having blades 30 which is adapted to be pinned to the shaft 33 upon assembly by means of the pin 31. The impeller is provided with an elongated cuplike housing I20 for receiving the seal. The open end of the housing I20 overlaps and embraces the adjacent end of the bearing 32 against which the carbon sealing washer II3 abuts. Said washer is provided with projections I25 which extend through the radially disposed longitudinal slots I24 formed in the housing I20.

To maintain the sealing unit in place before assembly with the shaft, there is a locking ring similar flexible material, having the semi-rigid ring Ill at one end and a similar ring III at the other end provided with the annular ribs bearing directly against the face of the washer H3, and including the outer and inner neck portions III and H3 respectively and the flexible shoulder H3. It also embodies the said compression spring I26, spring guide or sleeve I21 and clamp ring I20.

In practice, the seal is assembled within the impeller and locked therein by the locking ring 30, as illustrated in Fig. 5, at the source of manufacture. This unit may be furnished as a replacement part, whereupon the mechanic, in assembling it in the pump, need only remove. the bolts 34 in the outer housing, slip the pump with the seal in place over the end of the shaft 33 and insert the pin 31 therein. While it has herein been illustrated as being locked by the pin 31, the impeller may be secured upon the shaft in any other manner desirable.

A further advantage of this arrangement of the seal as a unitary part of the impeller and within the pump chamber 3i, is that it eliminates any danger of rusty particles or grit carried by the water from entering the seal and affecting the flexible parts thereof. To this extent it differs from the structure illustrated in Figs. 1 to 4, inclusive, wherein it is possible for water or moisture to enter the seal between the shaft I0 and the surface of the washer I3.

It is to be noted, however, that in the structures of Figs. 5 and 6 this cannot occur since at one end there is a seal between the washer H3 and the end of the bearing 32, while at the other end there is a definite seal between the flexible member and the shaft.

The invention claimed is:

1. In a fluid seal, the combination with shaft and housing members rotatable relative to each other, of a sealing washer mounted about said shaft to bear against the ends of the housing member, a cup-shaped metal closure having one end keyed to one of said rotatable members, a rubber sealing member mounted in said closure having oppositely-disposed ring portions, intermediate reduced and enlarged portions with a collapsible shoulder portion therebetween, said reduced portion bearing upon the periphery of the shaft in sealing engagement therewith, the ring of the enlarged portion bearing against the washer in sealing engagement and the collapsible shoulder portion being reversed upon itself when in'operating position to permit longitudinal displacement while maintaining the reduced sealing portion in compressed engagement with the shaft, and a compressible spring surrounding said member interposed between the end of the closure and the enlarged sealing ring for exerting pressure thereon to maintain said flexible member and washer and said washer and housing member in sealing engagement.

2. In a fluid seal, the combination with a shaft and housing members rotatable relative to each other, of a sealing washer mounted about said shaft to bear against the end of the housing member, a cup-shaped metal closure having a closed end keyed to one of said'rotatable members, a tubular rubber sealing sleeve mounted in said housing having oppositely-disposed ring portions and an intermediate reduced portion with a flexible shoulder, said reduced portion bearing upon the periphery of the shaft throughout a substantial portion of its length in sealing engagement therewith. one of said ring portions bearing against the washer in sealing engagement and the shoulder portion being reversible upon itself to permit of longitudinal' displacement while maintaining the reduced sealing portion in compressed engagement with the shaft, and a compressible spring surrounding said sleeve interposed between the closed end of the closure and the sealing washer for exerting pressure thereon to maintain said sleeve and washer and said washer and housing member in sealing engagement.

3. In a fluid seal, the combination with a shaft and housing members rotatable relative to each other, of a sealing washer mounted intermediate reduced portion joined to one of said ring portions by a flexible shoulder, said reduced portion extending in sealing engagement with the shaft throughout a substantial portion of its length, and the ring portion on said flexible shoulder fixedly bearing against said to sealing washer and movable therewith longi-. tudinally of the shaft through the flexibility of said shoulder.

CARL J. WINKLER. 

